The sarnie seller said it has already activated the service in 60 of its Blighty stores and plans to roll out free Wi-Fi access to another 70 outlets over the coming week.

UK wireless web service provider The Cloud struck a five-year deal (financial terms of which were kept secret) with Pret to connect its wireless service in-store.

While smaller, independent cafes and sandwich shops are more likely to offer free Wi-Fi to get customers through the door, larger food retailers have tended to be more reluctant to offer such a service.

Caffè Nero, for example, offers a wireless service in-store that’s provided by BT Openzone, but it doesn’t come cheap. Customers can expect to cough up around £5 for an hour’s surfing while gulping down their Orange Mocha Frappuccinos.

Similarly, Starbucks also squeezes out a few fast bucks pounds from the Wi-Fi service it offers through T-Mobile in its outlets.

But it’s unclear at this stage how much cash Pret will actually rake in from what it is doubtless hoping will be a stampede of people clamouring for free Wi-Fi with their egg mayo sarnies and cups of chai.

Here's a hint, though: Burger flipper McDonalds, which owns a 33 per cent stake in Pret, struck a similar deal with The Cloud last year, pitting itself against Starbucks' pay-as-you-go T-Mobile service for High Street internet supremacy. ®